1. Field of the Invention
This invention relates to lung exercisers for providing incentive feedback to patients engaged in remedial breathing exercises. In particular, this invention relates to lung exercisers utilizing inhaled air volume measurement and display for goal setting during breathing exercises.
2. Background of the Invention
Incentive spirometers are used by convalescing patients to measure progress and provide incentive for proper lung exercising. For example, post-operative patients who have undergone abdominal surgery can take only shallow breaths to avoid pain in the surgical site. This shallow breathing causes collapse and eventual necrosis of the lung alveoli, referred to as atelactasis. The shallow breathing also slows down the patient's recovery rate. To avoid atelactasis and to speed up recovery, the currently accepted technique is to encourage the patient to take slow deep breaths. Lung exercising devices that encourage patients to take deep breaths are known as incentive spirometers.
The prior art lung exercisers may be classified as either flow measuring or volume measuring devices. Flow measuring lung exercisers are commonly inexpensive, toy-like devices. For example, a simple flow measuring lung exerciser may comprise a mouthpiece and tube attached to a larger tube with a lightweight ball inside. Suction on the mouthpiece creates a partial vacuum which causes the ball to rise, thereby giving a rough indication of the air flow rate through the tube. Such air flow measuring lung exercisers suffer from the disadvantage of only encouraging rapid inhalation whereas the desired breathing procedure is taking slow deep breaths. Furthermore, such inexpensive flow measuring lung exercisers are of questionable incentive due to the crude feedback provided and due to their toy-like appearance. In particular, for younger children a more sophisticated, electronic incentive display is desired.
Prior art volume measuring incentive spirometers currently in use are expensive, relatively bulky devices. As a result, this type of spirometer is normally taken from patient to patient by a therapist as the cost is prohibitive to each patient having their own incentive spirometer. One type of such spirometer in common use measures volume by counting the number of revolutions of a turbine placed in a disposable air flow tube through which the patient inhales. The accuracy of this device depends upon the friction in the bearings and the inertia of the turbine. The reusable part of the unit employs a microcomputer to analyze the information from the turbine and provide a feedback display to the patient. Although the feedback provided is reasonably accurate, the overall device is bulky and expensive. Also, the device permits stacking of breaths. The patient can take several short breaths before the turbine stops spinning. This would show up as one deep breath.